The present invention relates to the field of industrial engineering, and more specifically, to the particular facet of that field dealing with the time-motion analysis of work functions in which an operator performs the same task, comprising one or more manipulative steps, over a substantial period of time.
In the past, a typical time-motion analysis, or time study, was carried out almost totally manually by the industrial engineer. After initial preparation for the study, in which the engineer determined the particular motions he was going to measure, he would undertake the study, during which he would stand at the operator's shoulder, or some other place from which he could conveniently observe the operator's work motion, to measure with a stopwatch the amount of time each step in the operator's performance took and record the measurements on a chart. For example, if the engineer is conducting a time study of an operator who is sewing pockets on shirts, he might record the time it took the operator to carry out each of the steps of picking up a pocket and shirt to be sewn, aligning the pocket in the proper location on the shirt, stitching each of the various edges of the pocket, and disposing of the finished shirt. Once the engineer had measured a number of operations over a particular length of time, e.g., one hour, the engineer would then return to his office where he would calculate the results of the measurements he had just taken. Typically, the calculation would require at least another hour of the engineer's time, and could take as much as three to four hours. Once the engineer had calculated the results of the study, and obtained the data he needed for analysis, he could return to discuss the results of the study with the operator, or present them to management for their use.
One of the major difficulties faced by an industrial engineer is the effective communication of the results of his study to the operator whom he has observed. Usually the time study will result in a substantial amount of data consisting mainly of numbers indicating, for example, the average time it took the operator to complete work on each garment, the average time it took for each step in the work process, the operator's best and worst times for each step, and the operator's expected output over the course of a week, month, or year based upon the measurements taken during the study. Often, a numerical feedback of this sort does not have much meaning for the operator, who is not trained in the analysis of statistical data and cannot use such data to pinpoint areas for improvement.
Another problem that is faced by the industrial engineer relates to the credibility that the operator is willing to give to the results obtained by the engineer. For example, as a result of his study, the engineer might determine that the operator's time for a particular step is longer than the standard time based on an average of all observed workers. He further might suggest to the operator that if the operator were to decrease his time on this step, he would be able to process a greater number of garments per day, and thus would set the operator's daily quota at this figure. However, the operator may not be willing to accept the determinations and suggestions given by the engineer. For example, he may think that the engineer was not operating the stopwatch at the correct times and therefore is not willing to place any weight on the numbers generated as a result of the engineer's study. Furthermore, he may consider the engineer's suggestion of a production quota to be too subjective, and thus might feel that it is unfair.
Typically, once a time study is completed, the operator might ask the Engineer how his performance rated. However, due to the time required by the engineer to calculate the results of his measurements before he can present them to the operator, he cannot immediately answer the operator's question. Furthermore, by the time he does return with the results, the operator may have lost interest in the purpose of the study, or the style of the garment may have changed to such a degree that the results of the study are no longer applicable.
Thus, as a result of these difficulties faced by the industrial engineer, the final step of the time study process, the acceptance of his suggestions by the operator who has been studied, and by management, could often take up to several months because of the lack of credibility that the study is initially greeted with. It is this final phase of acceptance of the results of time-motion analysis that limits the industrial engineer's effectiveness.
More recently, developments have appeared which facilitate the industrial engineer's task of conducting time studies. One of these developments is the portable data entry terminal, which consists of one or more standard electronic timers that can be key actuated to automatically record the elapsed time for each manipulative step in the work process. By freeing the engineer from the requirements of having to manually control a plurality of stopwatches and enter the time-related data on a chart, the engineer is able to concentrate more of his time on the observation of the operator's methods, and thus is not as likely to miss the occurrence of a particular event.
While these data entry terminals are advantageous in this respect, they still do not overcome the major difficulties faced by the engineer. Specifically, they still require a specific amount of time for calculation to be undertaken by the engineer at the end of the study, either with or without the assistance of a computer, before the results of the study can be presented to the operator. Furthermore, the results of the study obtained with the time study board are the same as those from a manual time study, i.e., data consisting of numbers relating to time measurements. Thus, although the data entry terminal assists the engineer in the recording of data, it does not help to overcome the problems associated with communication and credibility.
It is therefore a general object of the present invention to provide a novel time-motion analysis system in which the results of a time study are calculated immediately at the place where the study was conducted, e.g., on the shop floor, at the end of the study. As a further feature, the calculated results are communicated to the operator in a visual and personalized manner such that the operator can readily understand the factors that are of concern to the industrial engineer, accept the results of the study, gain useful insights into self-improvement and effectively participate in the determination of his quota.
It is another object of the present invention to provide such a system in which the input and intervention by the industrial engineer is kept to a minimum while increasing the interaction between the operator and the system, to thereby increase the credibility of the evaluation and analysis of the operator's performance and provide a learner based teaching aid.
It is a further object of the present invention to utilize instant replay video techniques for the self-analysis and self-training of operators in a manner that enhances self-motivation and productivity improvement.
Video systems have been used in the past as a training tool. In these systems, a recording is made of operators performing a task for which others are to be trained. Once the recording is made, for example on video tape, it is usually edited, and further processed to provide titles, graphical data, etc. This editing and processing step usually results in the expiration of a substantial amount of time between the recording of the operators performance and its subsequent playback. Hence, this conventional type of video teaching system may have some value in the training of new operators, but generally is not useful as an analysis tool in the time study environment, because it does not operate on a real time basis.
It is therefore yet a further object of the present invention to provide a novel time-motion analysis system that operates on a real time basis and provides instantaneous feedback to the operator so that the results of the observation of his work habits will be presented to him at a time when he is most interested in it and able to appreciate its value.
It is still another object of the present invention to provide a novel time-motion analysis system that affords instantaneous random access to multiple format responses in a realtime, instant replay mode.
It is yet another object of the present invention to provide a time-motion analysis system that renders useful feedback information for people other than the operator, including the industrial engineer and quality control personnel, in a timely fashion.